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Summer Arctic cyclone among largest ever recorded

The early August cyclone that spun out of Russian waters and over the Arctic Ocean was among the three strongest recorded in summer since monitoring began in 1979, but it surprised scientists for other reasons too. The loss of Arctic sea ice to global warming doesn't seem to have fueled the storm, reports Ars Technica, though the cyclone did cause breakup of thin ice and contributed to the year's record low ice extent.

A notable thing about the storm is that it did not seem to involve a large redistribution of atmospheric heat content. Storms like hurricanes famously take the energy from warm surface waters and redistribute it to the atmosphere. But readings from the Arctic Cyclone showed that the heat flux was small for most of its history. This suggests that the storm wasn't powered by the ocean below it, which in turn indicates that the loss of ice wasn't a factor in driving the storm's unusual strength. As the authors put it, "This leads to the view that it was the enhanced influence of the cyclone which contributed to the reduction in ice area, rather than low sea ice area being responsible for releasing energy to maintain the system."

Scientists have theorized that another contributor to quicker-than-expected ice loss in the Arctic is thinning ice that is letting more sunlight through to the water below, which is absorbing the heat and melting the ice even faster. A first-of-its-kind study published this week and reported by The New York Times seems to confirm that.

This means that the more the ice melts in late summer, the more first-year ice replaces multiyear ice, and the warmer the ocean beneath the ice becomes, accelerating the melting process. One sentence of the study says it all: “a continuation of the observed sea-ice changes will increase the amount of light penetrating into the Arctic Ocean, enhancing sea-ice melt and affecting sea-ice and upper-ocean ecosystems.”